From    the   ''Fortnightly    Ri-vifw,"   for   February,    1869. 


07V"   (-r^E 


Vc- 


Physical   JBasis  of  Life 


r.  H.  FIUXLEY,  LL.  D.,  F.  R.  S. 


|]:ile  (t,oilec|c,  ^eir  jharen,  :(),onn.  : 

T  H  TG     C  C>  Tj  L  IT,  G-  iHi     C  O  TJ  R  A  ]Sr  T 

i86g. 


From  the  "Fortnightly  Review,"  for  February,    1869. 


OJ<r    Ql^B 


Physical  Basis  of  Life. 


BY 


T.  H.  HUXLEY,  LL.  D.,  F.  R.  S. 


THE     dOXjLElQ-E     COTJR^ICXi 


INTRODUCTION 


The  following  remarkable  discourse  was  originally  delivered  in  Edin- 
burgh, Nov.  18th,  1868,  as  the  first  of  a  series  of  Sunday  evening  addresses, 
upon  non-religious  topics,  instituted  by  the  Rev.  J.  Cranbrook.  It  was 
subsequently  published  in  London  as  the  leading  article  in  the  FortnigMly 
Review,  for  February,  1869,  and  attracted  so  much  attention  that  five  edi- 
tions of  that  number  of  the  magazine  have  already  been  issued.  It  is  now 
re-printed  in  this  country,  in  permanent  form,  for  the  first  time,  and  will 
doubtless  prove  of  great  interest  to  American  readers.  The  author  is 
Thomas  Henry  Huxley,  of  London,  Prof,  of  Natural  History  in  the  Royal 
School  of  Mines,  and  of  Comparative  Anatomy  and  Physiology  in  the  Royal 
College  of  Surgeons.  He  is  also  President  of  the  Geological  Society  of  Lon- 
don. Although  comparatively  a  young  man,  his  numerous  and  valuable 
contributions  to  Natural  Science  entitle  him  to  be  considered  one  of  the 
first  of  living  Naturalists,  especially  in  the  departments  of  Geology  and 
Palaeontology,  to  which  he  has  mainly  devoted  himself.  He  is  un- 
doubtedly the  ablest  English  advocate  of  Darwin's  theory  of  the  Origin  of 
Species,  particularly  with  reference  to  its  application  to  the  human  race, 
which  he  believes  to  be  nearly  related  to  the  higher  apes.  It  is,  indeed, 
through  his  discussion  of  this  question  that  he  is,  perhaps,  best  known  to 
the  general  public,  as  his  late  work  entitled  "  Man's  Place  in  Nature,"  and 


other  writings  on  similar  topics,  have  been  very  widely  read  in  this  country 
and  in  Europe.    In  the  present  lecture  Professor  Huxley  discusses  a  kin- 
dred subject  of  no  less  interest  and  importance,  and  should  have  an  equally 
candid  hearing. 
Yat^k  College,  March  30^A,  1869. 


■'    Library* 

ON  THE  PHYSICAL  BASIS  OF  JJFE. 


Ill  order  to  make  the  title  of  tliis  discourse  generally  intel- 
ligible, I  have  translated  the  term  "Protoplasm,"  which  is  the 
scientific  name  of  the  substance  of  which  I  am  about  to  speak, 
by  the  words  "the  physical  basis  o|^j^^  I  suppose  that,  to 
many,  the  idea  that  there  is  such  ^^^^^^^  physical  basis,  or 
matter,  of  life  may  1)0  novel — so  A^^^^^^^Pd  is  the  conception 
of  life  as  a  sometliing  whicli  works^^^^Hr  matter,  but  is  inde- 
pendent of  it ;  and  even  those  wh(^reaware  that  matter  and 
life  are  inseparably  connected,  may  not  be  prepared  for  the  con- 
clusion plainly  suggested  by  the  phrase  "  the  physical  basis  or 
matter  of  life,"  that  there  is  some  one  kind  of  matter  which  is 
common  to  all  livino-  beino-s,  and  that  their  endless  diversities  are 
bound  together  by  a  physical,  as  well  as  an  ideal,  unity.  In  fact, 
when  first  apprehended,  such  a  doctrine  as  this  appears  almost 
shocking  to  common  sense.  ^  What,  truly,  can  seem  to  be  more 
obviously  different  from  one  another  in  faculty,  in  form,  and  in 
substance,  than  the  various  kinds  of  living  beings  ?  What  com- 
munity of  faculty  can  there  be  between  the  brightly-colored 
lichen,  which  so  nearly  resembles  a  mere  mineral  incrustation  of 
tlic  bare  rock  on  which  it  grows,  and  the  painter,  to  whom  it 
is  instinct  with  beauty,  or  the  botanist,  whom  it  feeds  Avitli 
knowledge  ? 

Again,  think  of  the  microscopic  fungus — a  mere  infinitesimal 
ovoid  particle,  which  finds  space  and  duration  enough  to  multiply 
into  countless  millions  in  the  body  of  a  living  fly;  and  then  of 
the  wealth  of  foliage,  the  luxuriance  of  flower  and  fruit,  which 
lies  between  this  bald  sketch  of  a  plant  and  the  giant  pine  of 
California,  towering  to  the  dimensions  of  a  cathedral  spire,  or  the 
Indian  fig,  which  covers  acres  with  its  profound  shadow,  and  en- 
dures while  nations  and  empires  come  and  go  around  its  vast 
circumference '?  Or,  turning  to  the  other  half  of  the  world  of 
life,  picture  to  yourselves  the  great  Finner  whale,  hugest  of 
beasts  that  live,  or  have  lived,  disporting  his  eighty  or  ninety  feet 
of  1)one,  muscle  and  l)lubber,  with  easy  roll,  among  waves  in  which 


tlie^stoutest  sliii^  that  ever  left  dockyard  would  founder  hopelessly ; 
and  contrast  hhn  with  the  invisible  animalcules — mere  gelatinous 
specks,  multitudes  of  which  could,  in  fact,  dance  upon  the  point 
of  a  needle  with  the  same  ease  as  the  angels  of  the  schoolmen 
could,  in  imagmation.  With  these  images  before  your  minds, 
you  may  well  ask  what  community  of  form,  or  structure,  is  there 
between  the  animalcule  and  the  whale,  or  between  the  fungus  and 
the  fig-tree?     And,  a  fortiori^  between  all  four? 

Finally,  if  we  regard  substance,  or  material  composition, 
what  hidden  bond  can  connect  the  flower  which  a  girl  wears  in 
her  hair  and  the  blooc^^ych  courses  through  her  youthful  veins ; 
or,  what  is  there  ^^^^^^^^  between  the  dense  and  resisting 
mass  of  the  oak,  o^^^^^^^g  fabric  of  the  tortoise,  and  those 
broad  disks  of  glasl^^^^^Kich  may  be  seen  pulsating  through 
the  waters  of  a  calm  s^^HI  Avhich  drain  away  to  mere  films  in 
the  hand  which  raises  them  out  of  their  element  ?  Such  objec- 
tions as  these  must,  I  think,  arise  in  the  mind  of  every  one  who 
ponders,  for  the  first  time,  uj^on  the  conception  of  a  single  phys- 
ical basis  of  life  underlying  all  the  diversities  of  vital  existence ; 
but  I  propose  to  demonstrate  to  you  that,  notwithstanding  these 
apparent  difficulties,  a  threefold  unity — namely,  a  unity  of  power 
or  faculty,  a  unity  of  form,  and  a  unity  of  substantial  composi- 
tion— does  pervade  the  whole  living  world.  Ko  very  abstruse 
argumentation  is  needed,  in  the  first  place,  to  prove  that  the 
powers,  or  faculties,  of  all  kinds  of  living  matter,  diverse  as  they 
may  be  in  degree,  are  substantially  similar  in  kind.  Goethe  has 
condensed  a  survey  of  all  the  powers  of  mankind  into  the  well- 
known  epigram : 

"  Warum  treibt  sicli  das  Volk  so  unci  schreit  ?    Es  will  sicli  ernitliron 
Kinder  zeugen,  und  sie  nahren  so  gut  es  vermag. 

Weiter  bringt  es  kein  Mensch,  stelV  er  sicli,  Avie  er  audi  will." 

In  physiological  language  this  means,  that  all  the  multifarious 
and  complicated  activities  of  man  are  comprehensible  under  three 
categories.  Either  they  a^b  immediately  directed  towards  the 
maintenance  and  development  of  the  body,  or  they  effect  trans- 
itory changes  in  the  relative  positions  of  parts  of  the  body,  or 
they  tend  towards  the  continuance  of  the  species.  Even  those 
manifestations  of  intellect,  of  feeling,  and  of  will,  which  Ave 
riffhtlv  name  the  hiirher  faculties,   are  not  excluded  from  tliis 


7 

classification,  iiiasmucli  as  to  every  one  but  tlie  subject  of  tliem, 
they  are  known  only  as  transitory  changes  in  the  relative  posi- 
tions of  parts  of  the  body.  Speech,  gesture,  and  every  other 
form  of  human  action  are,  in  the  long  run,  resolvable  into  muscu- 
lar contraction,  and  muscular  contraction  is  but  a  transitory  change 
in  the  relative  positions  of  the  parts  of  a  muscle.  But  the  scheme, 
which  is  large  enough  to  embrace  the  activities  of  the  highest 
form  of  life,  covers  all  those  of  the  lower  creatures.  The  lowest 
plant,  or  animalcule,  feeds,  grows  and  reproduces  its  kind.  In 
addition,  all  animals  manifest  those  transitory  changes  of  form 
which  we  class  under  irritability  and  contractility ;  and  it  is  more 
than  probable,  that  when  the  veget^ifo^fi^ld  is  thoroughly  ex- 
plored, we  shall  find  all  plants  in  poJR^^s^^^f  the  same  powers, 
at  one  time  or  other  of  their  existei]^H  'Pam  not  now  alluding 
to  such  phenomena,  at  once  rare  and  conspicuous,  as  those  ex- 
hibited by  the  leaflets  of  the  sensitive  plant,  or  the  stamens  of 
the  barberry,  but  to  much  more  widely-spread,  and,  at  the  same 
time,  more  subtle  and  hidden,  manifestations  of  vegetable  con- 
tractility. You  are  doubtless  aware  that  the  common  nettle  owes 
its  stinghig  property  to  tlie  innumerable  stifl"  and  needle-like, 
though  exquisitely  delicate,  hairs  which  cover  its  surface.  Each 
stinging-needle  tapers  from  a  broad  base  to  a  slender  summit, 
which,  though  rounded  at  the  end,  is  of  such  microscopic  fineness 
that  it  readily  penetrates,  and  breaks  ofii"  in,  the  skin.  The  wliole 
hair  consists  of  a  very  delicate  outer  case  of  wood,  closely  applied 
to  the  inner  surface  of  which  is  a  layer  of  semi-fluid  matter,  full  of 
innumerable  granules  of  extreme  minuteness.  This  semi-fluid 
lining  is  protoplasm,  which  thus  constitutes  a  kind  of  bag,  full  of 
a  limpid  liquid,  and  roughly  corresponding  in  form  with  the  inte- 
rior of  tlie  hair  which  it  fills.  When  viewed  with  a  sufiiciently 
liigh  magnifying  power,  the  protoplasmic  layer  of  the  nettle  hair 
is  seen  to  be  in  a  condition  of  unceasing  activity.  Local  con- 
tractions of  the  whole  thickness  of  its  substance  pass  slowly  and 
gradually  from  point  to  point,  and  give  rise  to  the  appearance  of 
progressive  waves,  just  as  the  bending  of  successive  stalks  of 
corn  by  a  breeze  produces  the  apparent  billows  of  a  corn-field. 
But,  in  addition  to  these  movements,  and  independently  of  them, 
the  granules  are  driven,  in  relatively  rapid  streams,  through 
channels  in  the  protoplasm  which  seem  to  have  a  considerable 
amount  of  persistence.  Most  commonly,  the  currents  in  adjacent 
parts  of  the  protoplasm  take  similar  directions ;  and,  thus,  there 


is  a  general  stream  up  one  side  of  the  hair  anxl  down  the  otlier. 
But  this  does  not  prevent  the  existence  of  partial  currents  which 
take  different  routes;  and,  sometimes,  trains  of  granules  niav  be 
seen  coursing  swiftly  in  opposite  directions,  Avithin  a  twenty- 
thousandth  of  an  inch  of  one  another;  while,  occasionally,  oppo- 
site streams  come  into  direct  collision,  and,  after  a  longer  or 
shorter  struggle,  one  predominates.  The  cause  of  these  currents 
seem  to  lie  in  contractions  of  the  protoplasm  wliicli  bounds  the 
channels  in  which  they  flow,  but  wdiicli  are  so  minute  that  the 
best  microscopes  show  only  their  effects,  and  not  themselves. 

The  spectacle  afforded  by  the  wonderful  energies  prisoned 
within  the  compass  of  the  jnicroscopic  hair  of  a  plant,  which  we 
commonly  regard  as^  mei^y  passive  organism,  is  not  easily  for- 
gotten by  one  who  has  watched  its  display  continued  hour  after 
hour,  without  pause  or  sign  of  w^eakening.  The  possible  com- 
plexity of  many  other  organic  forms,  seemingly  as  simple  as  the 
protaplasm  of  the  nettle,  dawns  upon  one  ;  and  the  comparison  of 
such  a  protoplasm  to  a  body  with  an  internal  circulation,  which 
has  been  put  forward  by  an  eminent  physiologist,  loses  much  of 
its  startling  character.  Currents  similar  to  those  of  tlie  hairs  of 
the  nettle  have  been  observed  in  a  great  midtitude  of  very  dif- 
ferent plants,  and  weighty  authorities  have  suggested  that  they 
probably  occur,  in  more  or  less  perfection,  in  all  young  vegetable 
cells.  If  such  be  the  case,  the  wonderful  noonday  silence  of  a 
tropical  forest  is,  after  all,  due  only  to  tlie  dullness  of  our  hear- 
ing ;  and  could  our  ears  catch  the  murmur  of  these  tiny  mael- 
stroms, as  they  whirl  in  the  innumerable  myriads  of  living  cells 
which  constitute  each  tree,  wo  should  be  stunned,  as  with  the  roar 
of  a  great  city. 

Among  the  lower  plants,  it  is  the  rule  rather  than  tlie  ex- 
ception, that  contractility  should  be  still  more  openly  manifested 
at  some  periods  of  their  existence.  The  protoplasm  of  Algce  and 
Fungi  becomes,  mider  nniny  circumstances,  partially,  or  com- 
pletely, freed  from  its  woody  case,  and  exhibits  movements  of  its 
whole  mass,  or  is  proju'lled  by  the  contractility  of  one,  or  more, 
hair-like  prolongations  of  its  body,  Avliich  are  called  vibratile  cilia. 
And,  so  far  as  the  conditions  of  the  manifestation  of  the  phenom- 
ena of  contractility  have  yet  been  studied,  they  are  the  sani^ Jbr 
the  plant  as  for  the  animal.  Heat  .md  electric  shocks  influence 
both,  and  in  the  same  Avay,  though  it  ma)  be  in  different  degrees. 
It  is  by  no  means  my  intention  to  suggest  that  there  is  no  differ- 


9 

eiice  ill  faculty  between  the  lowest  plant  and  tlie  highest,  or  be- 
tween plants  and  animals.  But  the  difference  between  the  pow- 
ers  of  the  lowest  plant,  or  animal,  and  those  of  the  highest  is 
one  of  degree,  not  of  kind,  and  dejjends,  as  Milne-Edwards  long 
ago  so  well  pointed  out,  upon  the  extent  to  which  the  principle 
of  the  division  of  labor  is  carried  out  in  the  livhig  economy.  In 
the  lowest  organism  all  parts  are  competent  to  perform  all  func- 
tions, and  one  and  the  same  portion  of  protoplasm  may  succes- 
sively take  on  the  function  of  feeding,  moving,  or  reproducing 
apparatus.  In  the  highest,  on  the  contrary,  a  great  number  of 
parts  combine  to  perform  each  function,  each  part  doing  its  allot- 
ted share  of  the  work  with  great  accuracy  and  efficiency,  but 
being  useless  for  any  other  purpose.  On  the  other  hand,  not- 
withstanding all  the  fundamental  resemblances  which  exist  be- 
tween the  powers  of  the  protoplasm  in  plants  and  in  animals, 
they  present  a  striking  difference  (to  which  I  shall  advert  more 
at  length  presently,)  in  the  fact  that  plants  can  manufacture  fresh 
protoplasm  out  of  mineral  compounds,  whereas  animals  are 
obliged  to  procure  it  ready  made,  and  hence,  in  the  long  run,  de- 
pend upon  plants.  Upon  what  condition  this  difference  in  the 
powers  of  the  two  great  divisions  of  the  world  of  life  depends 
nothing  is  at  present  known. 

With  such  qualification  as  arises  out  of  the  last-mentioned 
fact,  it  may  be  truly  said  that  the  acts  of  all  living  things  are 
fundamentally  one.  Is  any  such  unity  predicable  of  their  forms? 
Let  us  seek  in  easily  verified  facts  for  a  rejjly  to  this  question. 
If  a  drop  of  blood  be  drawn  by  pricking  one's  finger,  and  viewed 
with  proper  precautions  and  under  a  sufficiently  high  microscopic 
power,  tliere  will  be  seen,  among  the  innumerable  multitude  of 
little,  circular,  discoidal  bodies,  or  corpuscles,  which  float  in  it 
and  give  it  its  color,  a  comparatively  small  number  of  colorless 
corpuscles,  of  somewhat  larger  size  and  very  irregular  shape.  If 
the  drop  of  blood  be  kept  at  the  temperature  of  the  body,  these 
colorless  corpuscles  will  be  seen  to  exhibit  a  marvelous  activity, 
changing  their  forms  with  great  rapidity,  drawing  in  and  thrust- 
ing out  prolongations  of  their  substance,  and  creeping  about  as 
if  they  were  independent  organisms.  The  substance  which  is 
thus  active  is  a  mass  of  protoplasm,  and  its  activity  differs  in  de- 
tail, rather  than  in  principle,  from  that  of  the  protoplasm  of  the 
nettle.  Under  sundry  circumstances  the  corpuscle  dies  and  be- 
comes distended  into  a  round  mass,  in  the  midst  of  which  is  seen 


10 

a  smaller  splierical  body,  which  existed,  but  was  more  or  less 
hidden,  in  the  living  corpuscle,  and  is  called  its  nucleics.  Cor- 
puscles of  essentially  similar  structure  are  to  be  found  in  the 
skin,  in  the  lining  of  the  mouth,  and  scattered  through  the  whole 
framework  of  the  body,  ^^'ay,  more;  in  the  earliest  condition 
of  the  human  organism,  in  that  state  in  which  it  has  just  become 
distinguishable  from  the  Qg^  in  which  it  arises,  it  is  nothing  but 
an  aggregation  of  such  corpuscles,  and  every  organ  of  the  body 
-was,  once,  no  more  than  such  an  aggregation.  Thus  a  nucleated  ( 
.mass  of  protoplasm  turns  out  to  be  what  may  be  termed  the  . 
structural  unit  of  the  human  body.  As  a  matter  of  fact,  the 
body,  in  its  earliest  state,  is  a  mere  multiple  of  such  units ;  and, 
in  its  perfect  condition,  it  is  a  multiple  of  such  units,  variously 
modified.  But  does  the  formula  which  expresses  the  essential 
structural  character  of  the  highest  animal  cover  all  the  rest,  as 
the  statement  of  its  powers  and  faculties  covered  that  of  all 
others  ?  Very  nearly.  Beast  and  fowl,  reptile  and  fish,  mollusk, 
worm,  and  polype,  ai-e  all  composed  of  structui-al  units  of  the 
same  character,  namely,  masses  of  protoplasm  with  a  nucleus. 
There  are  sundry  ver}^  low  animals,  each  of  which,  structurally^ 
is  a  mere  colorless  blood-corpuscle,  leading  an  independent  life. 
But,  at  the  very  bottom  of  the  animal  scale,  even  this  simplicity 
becomes  simplified,  and  all  the  phenomena  of  life  are  manifested 
by  a  particle  of  protoplasm  without  a  nucleus.  Xor  are  such 
organisms  insignificant  by  reason  of  their  want  of  complexity 
It  is  a  fair  question  whether  the  protoplasm  of  those  simplest 
forms  of  life,  which  people  an  immense  extent  of  the  bottom  of 
the  sea,  would  not  outweigh  that  of  all  the  higher  living  beings 
which  inhabit  the  land  put  together.  .Vnd  in  ancient  times,  no 
less  than  at  the  present  day,  such  living  beings  as  these  have 
been  the  greatest  of  rock  builders. 

What  has  been  said  of  the  animal  world  is  no  less  true  of 
plants.  Imbedded  in  the  protoplasm  at  the  broad,  or  attached, 
end  of  the  nettle  hair,  there  lies  a  spheroidal  nucleus.  Careful 
examination  further  proves  that  the  whole  substance  of  the  nettle 
is  made  up  of  a  repetition  of  such  masses  of  nucleated  proto- 
plasm, each  contained  in  a  wooden  case,  which  is  modified  in 
form,  sometimes  into  a  woody  fibre,  somethnes  into  a  duct  or 
spiral  vessel,  sometimes  into  a  i:>ollen  grain,  or  an  ovule.  Traced 
back  to  its  earliest  state,  the  nettle  arises  as  the  man  does,  in  a 
particle  of  nucleated  protoplasm.     And  in  the  lowest  plants,  as  in 


11 

the  lowest  animals,  a  single  mass  of  such  protoplasm  may  consti- 
tute the  whole  plant,  or  the  protoplasm  may  exist  without  a 
nucleus.  Under  these  circumstances  it  may  well  be  asked,  how 
is  one  mass  of  non-nucleated  protoplasm  to  be  distinguished  from 
another?  why  call  one  "  plant,"  and  the  other  "animal  ?"  The 
only  reply  is  that,  so  far  as  formSs  concerned,  plants  and  animals 
are  not  separable,  and  that,  in  many  cases,  it  is  a  mere  matter  of 
convention  whether  we  call  a  given  organism  an  animal  or  a  plant. 

There  is  a  living  body  called  uTJthaliwm  sejyticum^  which 
appears  upon  decaying  vegetable  substances,and  in  one  of  its  forms, 
is  common  upon  the  surface  of  tan  pits.  In  this  condition  it  iF> 
to  all  intents  and  purposes,  a  fungus,  and  formerly  was  always 
regarded  as  such ;  but  the  remarkable  investigations  of  De  Bary 
have  shown  that,  in  another  condition,  the  ^thallum  is  an  ac- 
tively locomotive  creature,  and  takes  in  solid  matters,  upon 
which,  apparently,  it  feeds,  thus  exhibiting  the  most  characteris- 
tic feature  of  auimality.  Is  this  a  plant,  or  is  it  an  animal?  Is 
it  both,  or  is  it  neither?  Some  decide  in  favor  of  the  last  suppo- 
sition, and  establish  an  intermediate  kingdom,  a  sort  of  biologi- 
cal No  Man's  Land  for  all  these  questionable  forms.  But,  as  it 
is  admittedly  impossible  to  draw  any  distinct  boundary  line 
between  this  no  man's  land  and  the  vegetable  world  on  the  one 
hand,  or  the  animal,  on  the  other,  it  appears  to  me  that  this  pro- 
ceeding merely  doubles  the  difficulty  which,  before,  was  single. 
Protoplasm,  simple  or  nucleated,  is  the  formal  basis  of  all  life. 
It  is  the  clay  of  the  potter:  which,  bake  it  and  paint  it  as  he 
will,  remains  clay,  separated  by  artifice,  and  not  by  nature,  from 
the  commonest  brick  or  sun-dried  clod.  Thus  it  becomes  clear 
that  all  living  powers  are  cognate,  and  that  all  living  forms  are 
fundamentally  of  one  character.  .^  -^  ^  ^^^^^^^  c^^^^^^^^^^..  ; 

The  researches  of  the  chemist  have  revealed  a  no  less  strik- 
ing uniformity  of  material  composition  in  living  matter.  In  per- 
fect strictness,  it  is  true  that  chemical  investigation  can  tell  us  lit- 
tle or  nothing,  directly,  of  the  composition  of  living  matter,  inas- 
much as  such  matter  must  needs  die  in  the  act  of  analysis,  and 
upon  this  very  obvious  ground,  objections,  which  I  confess  seem 
to  me  to  be  somewhat  frivolous,  have  been  raised  to  the  drawing 
of  any  conclusions  whatever  respecting  the  composition  of  actu- 
ally living  matter  from  that  of  the  dead  matter  of  life,  which 
alone  is  accessible  to  us.  But  objectors  of  this  class  do  not  seem 
to  reflect  that  it  is  also,  in  strictness,  true  that  we  know  nothing 


about  the  composition  of  any  body  whatever,  as  it  is.  Tlie  state- 
ment that  a  crystal  of  calc-spar  consists  of  carbonate  of  lime,  is 
quite  true,  if  we  only  mean  tliat,  by  appropriate  processes,  it  may 
be  resolved  into  carbonic  acid  and  quicklime.  If  you  pass  the 
same  carbonic  acid  over  the  very  quicklime  tlnis  obtained,  you 
will  obtain  carbonate  of  lime  again ;  but  it  will  not  be  calc-spar, 
nor  anything  like  it.  Can  it,  therefore,  be  said  that  cliemical 
analysis  teaches  nothing  about  the  chemical  composition  of  calc- 
spar  ?  Such  a  statement  would  be  absurd;  but  is  is  hardlv 
more  so  than  the  talk  one  occasionally  hears  about  tlie  uselessness 
of  applying  the  results  of  chemical  analysis  to  the  living  bodies 
which  have  yielded  them.  One  fact,  at  any  rate,  is  out  of  reach 
of  such  refinements,  and  this  is,  that  all  the  forms  of  protoplasm 
which  have  yet  been  examined  contain  the  four  elements,  carbon, 
hydrogen,  oxygen,  and  nitrogen,  in  very  complex  union,"  and 
that  they  behave  similarly  towards  several  reagents.  To  this 
complex  combination,  the  nature  of  which  has  never  been  deter- 
mined Tvith  exactness,  the  name  of  Protein  lias  been  appliec!. 
And  if  we  use  this  term  with  such  caution  as  may  properly  arise 
out  of  our  comparative  ignorance  of  the  things  for  which  it  stands, 
it  may  be  truly  said,  that  all  protoplasm  is  proteinaceous ;  or,  as 
the  white,  or  albumen,  of  an  egg  is  one  of  the  commonest  exam- 
ples of  a  nearly  pure  proteine  matter,  we  may  say  that  all  living 
matter  is  more  or  less  albuminoid.  Perhaps  it  would  not  yet  l>e 
safe  to  say  that  all  forms  of  j)rotoplasm  are  affected  by  the  direct 
action  of  electric  shocks ;  and  yet  the  number  of  cases  in  whicli 
the  contraction  of  protoplasm  sliown  to  be  effected  by  this  agency 
increases  every  day.  Nor  can  it  be  affirmed  with  perfect  confi- 
dence that  all  forms  of  protoplasm  are  liable  to  uiidergo  that  pecu- 
liar coagulation  at  the  temperature  of  40  degrees — 50  degrees 
centigrade,which  has  been  called  "heat-stiffening,"  though  Ktlhue''s 
beautiful  rescarclies  have  |»roved  this  occurrence  to  take  place  in 
so  many  and  such  diverse  living  beings,  that  it  is  hardly  rash  to 
expect  that  the  law  holds  good  for  all.  Enough  has,  perhaps, 
been  said  to  prove  the  existence  of  a  general  uniformity  in  tlu^ 
character  of  the  protoplasm,  or  physical  basis  of  life,  in  whatever 
group  of  living  beings  it  may  be  studied.  But  it  will  be  under- 
Btood  that  this  general  iiniformity  by  no  means  excludes  any 
amount  of  special  modifications  of  the  fundamental  substance. 
The  mineral,  carbonate  of  lime,  assumes  an  immense  diversity  of 
characters,  though  no  one  doubts  that  under  all  these  Protean 
changes  it  is  one  and  the  same  thing. 


13 

And  now,  wliat  is  the  ultimate  fate,  and  what  the  origin,  of  the 
matter  of  life  ?  Is_it,  as  some  of  the  older  naturalists  supposed, 
difluLised  throughout  the  universe  in  molecules,  Avhich  are  inde- 
structible and  unchangeable  in  themselves  ;  but,  in  endless  trans- 
migration, unite  in  innumerable  permutations,  into  the  diversified 
forms  of  life  we  know  ?  Or,  is  the  matter  of  life  com^posed  of  ordi- 
nary matter,  differing  from  it  only  in  the  manner  in  which  its 
atoms  are  aggregated.  Is  it  built  up  of  ordinary  matter,  and 
again  resolved  into  ordinary  matter  Avhcn  its  work  is  done? 
Modern  science  does  not  hesitate  a  moment  between  these  alter- 
natives.    Physiology  writes  over  the  portals  of  life 

"  Debemur  morti  nos  nostraque," 

with  a  profounder  meaning  tlian  the  Koman  poet  attached  to 
that  melancholy  line.  Under  whatever  disguise  it  takes  refuge, 
whether  fungus  or  oak,  worm  or  man,  the  living  protoplasm  not 
only  ultimately  dies  and  is  resolved  into  its  mineral  and  lifeless 
constituents,  but  is  always  dying,  aiid,  strange  as  the  jDaradox 
may  sound,  could  not  live  unless  it  died.  In  the  wonderful  story 
of  the  "  Peau  de  Chagrin,"  the  hero  becomes  possessed  of  a  magi- 
cal wild  ass's  skin,  which  yields  him  the  means  of  gratifying  all 
liis  wishes.  But  its  surface  represents  the  duration  of  the  propri- 
etors life  ;  and  for  everv  satisfied  desire  the  skin  shrinls 


s  m 


pro- 
portion to  the  intensity  of  fruition,  until  at  length  life  and  the 
last  handbreadth  of  the  "Peau  de  Chagrin,"  disappear  with  the 
gratification  of  a  last  wish.  Balzac's  studies  had  led  him  over  a 
wide  range  of  thought  and  speculation,  and  his  shadowing  forth 
of  physiological  truth  in  this  strange  story  may  have  been  inten- 
tional. At  any  rate,  the  matter  of  life  is  a  veritable  "Peau  de 
Cliagrin,"  and  for  every  vital  act  it  is  somewhat  the  smaller.  All 
work  implies  waste,  and  the  Avork  of  life  results,  directly  or  indi- 
rectly, in  the  waste  of  protoplasm.  Every  vv^ord  uttered  by  a 
speaker  costs  liim  some  physical  loss ;  and,  in  the  strictest  sense, 
he  burns  that  others  may  have  light — so  much  eloquence,  so  much 
of  his  body  resolved  into  carbonic  acid,  water  and  urea.  It  is 
clear  that  this  process  of  expenditure  cannot  go  on  forever.  But, 
happily,  the  protoplasmic  ;:>eaz«  de  chagrin  differs  from  Balzac's  in 
its  capacity  of  being  repaired,  and  brought  back  to  its  full  size, 
after  every  exertion.  For  example,  this  present  lecture,  what- 
ever its  intellectual  worth  to  you,  has  a  certain  j^hysical  value  to 
me,  which  is,  conceivably,  expressible  by  the  number  of  grains 


14 

of  protoplasm  and  other  bodily  substance  wasted  in  maintaining 
my  vital  processes  during  its  delivery.  My  peau  de  chagrin  will 
be  distinctly  smaller  at  the  end  of  the  discourse  than  it  was  as  the 
beginning.  By-and-by,  I  shall  probably  have  recourse  to  the  sub- 
stance commonly  called  mutton,  for  the  purpose  of  stretching  it 
back  to  its  original  size.  Xow  this  mutton  was  once  the  living 
protoplasm,  more  or  less  modified,  of  another  animal — a  sheep. 
As  I  shall  eat  it,  it  is  the  same  matter  altered,  not  only  by  death,  | 
but  by  exposure  to  sundry  artificial  operations  in  the  process  of 
cooking.  But  these  changes,  whatever  be  their  extent,  have  not 
rendered  it  incompetent  to  resume  its  old  functions  as  matter  of 
life.  A  singular  inward  laboratory,  which  I  possess,  will  dissolve 
a  certain  portion  of  the  modified  protoplasm,  the  solution  so  formed 
will  pass  into  my  veins ;  and  the  subtle  influences  to  which  it  will 
then  be  subjected  will  convert  the  dead  protoplasui  into  living 
protoplasm,  and  transubstantiate  sheep  into  man.  Nor  is  this  all. 
If  digestion  were  a  thing  to  be  trifled  with,  I  might  sup  upon  lob- 
ster, and  the  matter  of  life  of  the  crustacean  would  undergo  the 
same  wonderful  metamorphosis  into  humanity.  And  were  I  to 
return  to  my  own  place  by  sea,  and  undergo  shipwreck,  the  Crus- 
tacea might,  and  probably  would,  return  the  compliment,  and 
demonstrate  our  common  nature  by  turning  my  protoplasm 
into  living  lobster.  Or,  if  nothing  better  were  to  be  had,  I  might 
supply  my  wants  with  mere  bread,  and  I  should  find  the  proto- 
plasm of  the  wheat-plant  to  be  convertible  into  man,  with  no  more 
trouble  than  that  of  the  sheep,  and  with  far  less,  I  fancy,  than 
that  of  the  lobster.  Hence  it  appears  to  be  a  matter  of  no  gwat 
moment  wliat  animal,  or  what  plant,  I  lay  under  contributit^i  for 
protoplasm,  and  the  fact  speaks  volumes  for  the  general  identity 
of  that  substance  in  all  living  beings.  T  share  this  catholicity  of 
assimulation  with  other  animals,  all  of  whicli,  S(^  far  as  we  know, 
could  thrive  equally  well  on  the  protoi)lasni  of  any  of  their  fel- 
lows, or  of  any  plant ;  but  here  the  assimilative  [)Owers  of  the  ani- 
mal world  cease. 

A  solution  of  smelling-salts  in  water,  with  an  infinitesimal 
proportion  of  some  other  saline  matters,  contains  all  the  elemen- 
tary bodies  which  enter  into  the  composition  of  protoplasm ;  but, 
as  I  need  hardly  say,  a  hogshead  of  that  fluid  would  not  keep  a 
hungry  man  from  starving,  nor  would  it  save  any  animal  what- 
ever, from  a  like  fate.  An  animal  cannot  make  protoplasm,  but 
must  take  it  ready-made  from  some  othei'  animal,  or  some  plant— 


15 

the  aiiimars  highest  feat  of  constructive  chemistry  behig  to  con- 
vert dead  protoplasm  mto  that  living  matter  of  life  which  is 
appropriate  to  itself.  Therefore,  in  seeking  for  the  origin  of 
protoplasm,  we  must  eventually  turn  to  the  vegetable  world. 
The  fluid  containing  carbonic  acid,  water,  and  ammonia,  which 
oiFers  such  a  barmecide  feast  to  the  animal,  is  a  table  richly 
spread  to  multitudes  of  plants  ;  and  with  a  due  supply  of  only 
such  materials,  many  a  plant  will  not  only  maintain  itself  in 
vigor,  but  grow  and  multiply  until  it  has  increased  a  million-fold, 
or  a  million  million-fold,  the  quantity  of  protoplasm  which  it  orig- 
inally possessed  ;  in  this  way  building  up  the  matter  of  life,  to 
an  indefinite  extent,  from  the  common  matter  of  the  universe. 
Thus  the  animal  can  only  raise  the  complex  substance  of  dead 
protoplasm  to  the  higher  power,  as  one  may  say,  of  living  proto- 
plasm ;  w^hile  the  plant  can  raise  the  less  complex  substances — car- 
bonic acid,  water,  and  ammonia — to  thesame  stage  of  living  pro- 
toplasm, if  not  to  the  same  level.  But  the  plant  also  has  its  lim- 
itations. Some  of  the  fungi,  for  example,  appear  to  need  higher 
compounds  to  start  with  ;  and  no  known  j^lant  can  live  upon  the 
uncomj)ounded  elements  of  protoplasm,  A  plant  supplied  with 
pure  carbon,  hydrogen,  oxygen,  and  nitrogen,  phosphorus,  sul- 
phur, and  the  like,  would  as  infallibly  die  as  the  animal  in  his 
bath  of  smelling-salts,  though  it  would  be  surrounded  by  all  the 
constituents  of  protoplasm.  Nor,  indeed,  need  the  process  of 
simplification  of  vegetable  food  be  carried  so  lar  as  this,  in  order 
to  arrive  at  the  limit  of  the  plant's  thaumaturgy. 

Let  w^ater,  carbonic  acid,  and  all  the  other  needful  consti- 
tuents, be  supplied  without  ammonia,  and  an  ordinary  j)lant  will 
still  be  unable  to  manufacture  protoplasm.  }  Thus  the  matter  of 
life,  so  far  as  we  know  it  (and  we  have  no  right  to  speculate  on 
any  other)  breaks  up,  in  consequence  of  that  continual  death 
which  is  the  condition  of  its  manifesting  vitality,  into  carbonic 
acid,  water,  and  ammonia,  which  certainly  possess  no  j)roperties 
but  those  of  ordinary  matter.  And  out  of  these  same  forms  of 
ordhiary  matter,  and  from  none  which  are  simpler,  the  vegetable 
world  builds  up  all  the  protoplasm  which  keeps  the  animal  world 
agoing.  Plants  are  the  accumulators  of  the  power  which  animals 
distribute  and  disperse,  f    ^  ■*^fc^ 

But  it  wuU  be  observed,  that  the  exist^|||f  the  matter  of 
life  depends  on  the  pre-existence  of  certain  compoiuids.  namely, 
cal'bonic  acid,  water,  and  ammonia.     Withdraw  any  one  of  these 


16 

three  from  the  world  and  ail  vital  })heiioineiia  come  to  an  end. 
They  are  related  to  the  protoplasm  of  the  plant,  as  the  protoplasm 
of  the  plant  is  to  that  of  the  animal.  Carbon,  hydrogen,  oxygen, 
and  nitrogen  are  all  lifeless  bodies.  Of  these,  carbon  and  oxygen 
unite  in  certain  proportions  and  under  certain  conditions,  to  give 
rise  to  carbonic  acid  ;  hydrogen  and  oxygen  produce  water  ; 
nitrogen  and  hydrogen  give  rise  to  ammonia.  These  new  com- 
pounds, like  the  elementary  bodies  of  which  they  are  composed, 
are  lifeless.  But  when  they  are  brought  together,  under  certain 
conditions  they  give  rise  to  the  still  more  complex  body,  proto- 
plasm, and  this  protoplasm  exhibits  the  phenomena  of  life.  I  see 
no  break  in  this  series  of  steps  in  molecular  complication,  and  I 
am  unable  to  understand  why  tlie  language  which  is  applicable 
to  any  one  term  of  the  series  may  not  be  used  to  any  of  the  oth- 
ers. AYe  think  lit  to  call  different  kinds  of  matter  carbon,  oxygen, 
hydrogen,  and  nitrogen,  and  to  speak  of  the  various  powers  and 
activities  of  these  substances  as  the  properties  of  the  matter  of 
which  they  are  composed.  When  hydrogen  and  oxygen  are 
mixed  in  a  certain  proportion,  and  the  electric  spark  is  passed 
through  them,  they  disappear,  and  a  quantity  of  water,  equal  in 
weight  to  the  sum  of  their  weights,  appears  in  their  place.  There 
is  not  the  slightest  parity  between  the  passive  and  active  poAvers 
of  the  water  and  those  of  the  oxygen  and  hydrogen  v.hich  haA'e 
given  rise  to  it.  At  32  degrees  Fahrenheit,  and  far  below  that 
temperature,  oxygen  and  hydrogen  are  elastic  gaseous  bodies, 
whose  particles  tend  to  rush  away  from  one  another  with  great 
force.  Water,  at  the  same  temperature,  is  a  strong  though  brit- 
tle solid,  whose  particles  tend  to  cohere  into  dehnite  geometrical 
shapes,  and  sometimes  build  up  frosty  imitations  of  the  most 
complex  forms  of  vegetable  foliage.  Xevcrtheless  we  call  these, 
and  many  other  strange  phenomena,  the  properties  of  the  water, 
and  we  do  not  hesitate  to  believe  that,  in  some  way  or  another, 
they  result  from  the  properties  of  the  component  elements  of  the 
water.  We  do  not  assume  that  a  something  called  "  aquosity" 
entered  into  and  took  possession  of  the  oxide  of  hydrogen  as  soon 
as  it  was  formed,  and  then  guided  the  aqueous  ])articles  to  theii* 
])lac('S  ill  tlu'  facets  of  the  crysta],  or  amongst  the  leallets  of  tlie 
lioar-iVost.  On  the  contrary,  we  live  in  the  hope  and  in  the  faith 
that,  by  the  adv;vn|^  of  molecular  })hysics,  we  shall  by-and-by  be 
able  to  see  our  v>ny  as  clearly  from  the  constituents  of  Avater  to 
the  properties  of  water,  as  we  are  now  able  to  deduce  the  operations 


17 

of  a  wateli  fi-om  tlio  form  of  its  parts  and  the  manner  in  Avhicli 
they  are  pnt  touetliei-.  Ts  the,  case  in  any  way  changed  when 
carbonic  acid,  water,  and  ammonia  disappear,  and  in  tlieir  place, 
nn(Un-  the  intinence  of  pre-existing  living  ])rotoplasm,  an  equiva- 
K'nt  w  eiglit  of  the  matti^r  (1'  life  makes  its  appearance  ?  It  is  trne 
tliat.  there  is  no  sort  of  parity  between  tlie  ])roperties  of  the  com- 
ponents and  the  ])ro])erties  of  tlie  resultant,  but  neither  was 
tlieVe  in  the  case  of  the  water.  It  is  also  true  tluit  what  I  have 
s|)ol<en  of  as  the  influence  of  pre-existing  li\ing  matter  is  some- 
thing quite  uriintelligible ;  l)ut  does  anybody  quite  comprehend 
the  modus  operandi  of  an  electric  S])ark,  which  traverses  a  mix- 
ture of  oxygen  and  hydrogen  ?  Wliat  justification  is  there,  then, 
for  the  assnm])tion  of  the  existence  in  the  living  matter  of  a 
something  which  has  no  representative  or  correlative  m  the  not 
living  matter  whicli  gave  rise  to  it?  What  better  philosophical 
status  has  "  vitality"  than  "  aquosity  ?"  And  why  should 
^'  vitality"  hope  for  a  ])etter  fate  than  the  other  "  itys"  which 
have  disappeared  since  ]Martinus  Scriblerus  accounted  for  the 
operation  of  the  meat-jack  by  its  inherent  "  meat  roasting  qnal- 
ity,"  and  scorned  the  "materialism"  of  those  who  explained  the 
turning  of  the  s])it  by  a  cei-tain  mechanism  worked  by  the 
draught  of  the  chimney?  If  scientitic  language  is  to  possess  a 
definite  and  constant  signification  whenever  it  is  employed,  it 
seems  to  me  that  we  are  logically  bound  to  apply  to  tlie  proto- 
plasm, or  physical  ])asis  of  life,  the  same  conceptions  as  those 
which  are  held  to  be  legitimate  elsewhere.  If  the  phenomena 
exhibited  by  water  are  its  })roperties,  so  ai'c  tliose  presented  by 
])rotoplasm,  living  or  dead,  its  properties.  If  the  properties  of 
water  may  be  properly  said  to  result  from  the  nature  and  disposi- 
tion of  its  component  molecules,  I  can  find  no  intelligible  ground 
for  refusing  to  say  that  the  properties  of  proto])lasm  result  from 
the  nature  aiul^  dis])osition  of  jts^  molecules.  But  I  bid  you 
l)eware  that,  in  accepting  these  conclusions,  you  are  placing  your 
feet  on  the  first  rung  of  a  ladder  which,  in  most  people's  estima- 
tion, is  the  reverse  of  Jacob's,  and  leads  to  the  antipodes  of 
heaven.  It  may  seem  a  small  thing  to  admit  that  the  dull  vital 
actions  of  a  fungus,  or  a  foraminifer,  are  the  properties  of  their 
protoplasm,  and  are  the  direct  results  of  the  nature  of  the  mat- 
ter of  which  they  are  composed. 

l)Ut  if,  as  I  have  endeavored  to  prove  to  you,  their  proto- 
plasm is  essentially  identical  with, and  most  readily  converted  into, 


IS 

that  of  any  animal,  I  can  discover  no  logical  halting  place 
between  the  admission  that  snch  is  the  case,  and  the  further  con- 
cession that  all  vital  action  may,  with  equal  propriety,  he  said  to 
be  the  result  of  the  molecular  forces  of  the  pratoplasm  which  dis- 
plays it.  And  if  so,  it  must  be  true,  in  the  same  sense  and  to 
the  same  extent,  that  the  thoughts  to  which  I  am  noAV  giving 
utterance,  and  your  thoughts  regarding  them,  are  the  expression 
of  molecidar  changes  in  that  matter  of  life  which  is  the  source  of 
our  other  vital  phenomena.  Past  experience  leads  me  to  be  tolei'- 
ably  certain  that,  when  the  propositions  I  have  just  placed  before 
you  are  accessible  to  2:>ublic  comment  and  critieism,  they  will  be 
condemned  by  many  zealous  ]:)ersons,  and  pertiaps  by  some  few 
of  the  wise  and  thoughtful.  I  should  not  wonder  if  "  gross  and 
brutal  materialism"  Avere  the  mildest  phrase  applied  to  them  in 
certain  quarters.  And  most  imdoubtedly  the  terms  of  the  pro- 
positions are  distinctly  materialistic.  Nevertheless,  two  things 
are  certain  :  the  one,  that  I  hold  the  statements  to  be  substantially 
true ;  the  other,  that  I,  individually,  am  no  materialist,  but,  on 
the  contrary,  belicA^e  materialism  to  involve  grave  philoso]diical 
error. 

This  nnion  of  materialistic  terminology  with  the  repudia- 
tion of  materialistic  philosophy  I  share  with  some  of  the  most 
thoughtful  men  with  whom  I  am  acquainted.  And,  when  I  first 
undertook  to  deliver  the  present  discourse,  it  appeared  to  me  to 
be  a  fitting  opportunity  to  explain  how  such  an  union  is  not  only 
consistent  with,  but  necessitated  by  sound  logic.  T  pur])0sed  to 
lead  you  through  tlie  territory  of  vital  phenomena  to  the  materi- 
alistic slough  in  which  you  find  yourselves  now  plunged,  and  then 
to  point  out  to  you  the  sole  patli  by  which,  in  my  judgment, 
extrication  is  possible.  An  occurrence,  of  which  I  was  unaware 
until  my  arrival  here  last  night,  renders  this  line  of  argument  sin- 
gularly opportune.  I  found  in  your  papers  the  eloquent  address 
"  On  the  Limits  of  Philosophical  Inquiry,"  which  a  distinguished 
prelate  of  the  English  Church  delivered  before  the  members  of 
tlie  Philosophical  Institution  on  the  ])revious  day.  My  argument, 
also,  turns  upon  this  very  point  of  limits  of  philosophical  inquiry  ; 
and  I  cannot  bring  out  my  own  views  better  than  by  contrasting 
them  with  those  so  plainly,  and,  in  the  main,  fairly  stated  by  the 
Archbishop  of  York,  But  I  may  be  permitted  to  make  a  prelimi- 
nary comment  upon  an  occurrence  that  greatly  astonished  me. 
Applying  the  name  of  "the  Xew  Philosophy"  to  that  estimate  of 


10 

the  limits  of  pliilosopliical  inquiry  wliich  I,  iii  cOiiiiiion  with  many 
other  men  of  science,  hohl  to  be  just,  the  Archbishop  opens  his 
address  by  identifying  this  "  new  philosophy^'  with  the  positive 
philosophy  of  M.  Comte  (of  whom  he  speaks  as  its  "founder;") 
and  then  proceeds  to  attack  that  philosoper  and  his  doctrines 
vigorously.  Now,  so  far  as  I  am  concerned,  the  most  reverend 
prelate  might  dialectically  hew  M.  Comte  in  pieces,  as  a  modern 
^Vgag,  and  I  should  not  attempt  to  stay  his  hand.  In  so  far  as 
my  study  of  what  specially  characterizes  tlie  Positive  Philoso2:>hy 
has  led  me,  I  find  therein  little  or  nothing  of  any  scientific  value, 
and  a  great  deal  which  is  as  thoroughly  antagonistic  to  the  very 
essence  of  science  as  anything  in  ultramontane  Catholicism.  In 
fact,  M.  Comte's  philosophy  in  practice  might  be  compendiously 
described  as  Catholicism  onimis  Christianity.  But  what  has 
Comptism  to  do  with  the  "  Xew  Philosophy,"  as  the  Archbishop) 
defines  it  in  the  fi3llowing  passage  ? 

"  Let  me  briefly  remind  you  of  the  leading  principles  of  this 
new  philosophy. 

"  All  knowledge  is  experience  of  facts  acquired  by  the  senses. 
The  traditions  of  older  philosophies  have  obscured  our  ex2:>erience 
by  mixing  with  it  much  that  the  senses  cannot  observe,  and  until 
these  additions  are  discarded  our  knowledge  is  impure.  Thus, 
metaphysics  tell  us  that  one  fact  which  we  observe  is  a  cause, 
and  another  is  the  efl*ect  of  that  cause  ;  but  upon  a  rigid  analysis 
we  find  that  our  senses  observe  nothing  of  cause  or  effect ;  they 
observe,  first,  that  one  fact  succeeds  another,  and,  after  some  op- 
portunity, that  tliis  fact  has  never  failed  to  follow — that  for  cause 
and  effect  Ave  should  substitute  invariable  succession.  An  older 
philosophy  teaches  us  to  define  an  object  by  distinguishing  its 
essential  from  its  accidental  qualities ;  but  experience  knows 
nothing  of  essential  and  accidental ;  she  sees  only  that  certain 
marks  attach  to  an  object,  and,  after  many  observations,  that 
some  of  them  attach  invariably,  whilst  others  may  at  times  be 
absent.  *****  ^\^g  .j|  knowledge  is  relative,  the  not '.on 
of  anythhig  being  necessary  must  be  banished  with  other  tradi- 
tions." 

There  is  much  here  that  expresses  the  sj^irit  of  the  "  Xcw 
Philosophy,"  if  by  that  term  be  meant  the  spirit  of  modern  sci- 
ence ;  but  I  cannot  but  marvel  that  the  assembled  wisdom  and 
learning  of  Edinburgh  should  have  uttered  no  sign  of  dissent, 
when  Comte  was  declared  to  be  the  founder  of  these  doctrinesi 


20 

ISTo  one  will  accuse  Scou-hiiicn  oi'  liabilunlly  Ibro-cttiug  tlieir 
great  countrymen  ;  but  it  was  enough  to  nialvc  David  ITume  tui'u 
in  his  grave,  that  liei'e,  almost  ^vitliin  ear-sliot  of  liis  liouse,  an 
instructed  audience  sliouhl  liave  Jisteiied,  witliout  a  murmur, 
Avhile  his  most  characteristic  doctrines  were  attiibuted  to  a 
French  writer  of  fifty  yeai-s  later  date,  in  whose  dreary  and  ver])ose 
pages  we  miss  alike  the  vigor  of  thought  and  the  exquisite  clear- 
ness of  the  styhi  of  the  man  whonl  I  make  bold  to  term  the  most 
acute  thinker  of  the  eighteenth  century — even  though  that  cen- 
tury produced  Kant.  J>ut  I  did  not  come  to  Scotland  to  vindi- 
cate the  honor  of  one  of  the  greatest  men  she  has  ever  pi'oduced. 
My  business  is  to  point  out  to  you  that  the  only  way  of  escape 
out  of  the  crass  materialism  in  which  we  just  now  hmded  is  the 
adoption  and  strict  w^orking  out  of  the  very  principles  which  the 
Archbishop  holds  up  to  re})robation. 

Let  us  suppose  that  knowledge  is  absolute,  and  not  relative, 
and  therefore,  that  our  conception  of  matter  represents  that 
which  it  really  is.;  Let  us  suppose,  farther,  that  we  do  know 
more  of  cause  and  effect  than  a  certain  definite  order  of  succes- 
sion among  facts,  and  that  we  have  a  knowledge  of  the  necessity 
of  that  succession — and  hence,  of  necessary  laws — and  I,  for  my 
part,  do  not  see  what  escape  there  is  from  utter  materialism  and 
necessarianism.  For  it  is  obvious  that  our  knowledge  of  what 
■\ve  call  the  material  world  is,  to  begin  with,  at  least  as  certain 
and  definite  as  that  of  the  spiritual  world,  and  that  our  ac(piaint- 
ance  with  the  law  is  of  as  old  a  date  as  our  knowledge  of  spon- 
taneity. 

Further,    I   take    it  to   be   demonsti-able   that  it  is    uttei-ly 
impossible  to  prove  that  anything  whatever  may  not  be  the  effect 
of  a   material    and   necessary  cause,    and   that    human    logic   is 
equally  incompetent  to  prove  that  any  act  is  i-eall}-  spontaneous. 
A  really  spontaneous  act  is  one  whicli,  by  the  assumption,  has 
no  cause  ;  and  the  attempt  to  i)rove  such  a  negative  as  this  is, 
on  the  face  of  the  matter,  absurd.      And  while  it  is  thus  a  })hilo- 
sophical  impossibility  to  demonstrate  that  any  given  phenomenon  ; 
is  not  the  effect  of  a  material  cause,  any  one  who  is  acquainted  ! 
with  the  history  of  science  will  admit,  that    its  progi-ess  lias,  in 
all  ages,  meant,  and  now  more  than  ever,  means,  the  extension   : 
of  the  province  of  what  avc  call  matter  and  causation,  and  the    I 
concomitant    gradual    b.-uiislnnent    from    all   regions    of   human    t 
thought  of  what  we  call  spirit  and  spontaneity.  .^ 


21 

1  luivc  endeavored,  in  the  ti^^^t  \)[\vt  of  tliis  discourse,  to  give 
you  ii  conception  of  tlie  direction  towards  wliicli  modern  physi- 
ology is  tending  ;  and  I  ask  you,  wliat  is  tlie  difference  between 
the  conce])tion  of  life  as  the  2)roduct  of  a  certain  disposition  of 
material  molecules,  and  the  old  notion  of  an  ArchiBus  governing 
and  directing  blind  matter  Avithin  each  living  body,  except  this 
— that  here,  as  else^vhere,  matter  and  la^v  have  devoured  spirit 
and  spontaneity?  And  as  surely  as  every  future  grows  out  of 
past  and  present,  so  will  the  physiology  of  the  future  gradually 
extend  the  realm  of  matter  and  law  until  it  is  co-extensive  with 
knowledge,  witli  feeling,  and  with  action.  Tlie  consciousness  of 
this  great  truth  weighs  like  a  nightmare,  I  believe,  upon  many 
of  the  best  minds  of  these  days.  They  watch  what  they  con- 
ceive to  be  the  progress  of  materialism,  in  such  fear  and  power- 
less anger  as  a  savage  feels,  when,  during  an  eclipse,  the  great 
shadow  creeps  over  the  face  of  the  sun.  Tlie  advancing  tide  of 
matter  threatens  to  drown  their  souls  ;  the  tightening  grasp  of 
law  imi)edes  their  freedom ;  they  are  alarmed  lest  man's  moral 
nature  be  debased  by  the  increase  of  his  wisdom. 

Tf  the  "  Xev,'  Pliilosophy"  be  worthy  of  the  reprobation 
with  which  it  is  visited,  I  confess  their  fears  seem  to  me,  to  be 
well  founded.  While,  on  the  contrary,  could  David  Hume  be 
consulted,  I  think  lie  would  smile  at  their  perplexities,  and  chide 
them  for  doing  even  as  the  heathen,  and  falling  down  in  terror 
before  the  hideous  idols  their  own  hands  have  raised.  For,  after 
all,  what  do  we  know  of  this  terrible  "  matter,"  except  as  a 
name  for  the  unknown  and  hypothetical  cause  of  states  of  our 
own  consciousness  ?  And  what  do  we  know  of  that  "  spirit'' 
over  whose  threatened  extinction  by  matter  a  great  lamentation 
is  arising,  like  that  which  was  heard  at  the  death  of  Pan,  except 
that  it  is  also  a  name  for  an  unknown  and  hypothetical  cause,  or 
condition,  of  states  of  consciousness  ?  In  other  w*ords,  matter 
and  spirit  are  but  names  for  the  imaginary  substrata  of  groups  of 
natural  phenomena.  And  what  is  the  dire  necessity  and  "  iron" 
law  under  which  men  groan  ?  Truly,  most  gratuitously  invented 
bugbears.  I  suppose  if  there  l)e  an  "  iron"  law,  it  is  that  of 
gravitation ;  and  if  there  be  a  physical  necessity,  it  is  that  a 
stone,  unsuj^ported,  must  fall  to  the  ground.  But  Avhat  is  all  we 
really  know  and  can  know  about  the  latter  phenomenon  ?  fSim- 
ply,  that,  in  all  human  experience,  stones  have  fallen  to  the 
gi'ound  under  these  conditions ;  that  we  have  not  the  smallest 


22 

reason  for  believing  that  any  stone  so  eircnmstaneed  will  not  fall 
to  the  ground ;  and  that  we  liave,  on  the  contrary,  every  reason 
to  believe  that  it  will  so  fall.  It  is  very  convenient  to  indicate 
that  all  the  conditions  of  belief  have  been  fnlfilled  in  this  case, 
by  calling  the  statement  that  unsupported  stones  will  fall  to  the 
ground,  "  a  law  of  nature."  But  when,  as  commonly  happens, 
we  change  will  into  must,  we  introduce  an  i-dea  of  necessity 
which  most  assuredly  does  not  lie  in  the  ol)served  facts,  and  has 
no  warranty  that  I  can  discover  elsewhere.  For  my  part,  I 
utterly  repudiate  and  anathematise  the  intruder.  Fact  I  know  ; 
and  Law"  I  know ;  but  what  is  this  Xecessity,  save  an  empty 
shadow  of  my  own  mind's  throwing  ?  But,  if  it  is  certain  that 
w^e  can  have  no  knowledge  of  the  nature  of  either  matter  or 
spirit,  and  that  the  notion  of  necessity  is  something  illegitimately 
thrust  into  the  perfectly  legitimate  conception  of  law,  the  mate- 
rialistic position  that  there  is  nothing  in  the  world  bnt  matter, 
force,  and  necessity,  is  as  utterly  devoid  of  justiiication  as  the 
most  baseless  of  theological  dogmas. 

The  fundamental  doctrines  of  materialism,  like  those  of 
spiritualism,  and  most  other  "  isms,"  lie  outside  "  the  limits  of 
philosophical  inquiry,"  and  David  Hume's  great  service  to  human- 
ity is  his  irrefragable  demonstration  of  what  these  limits  are. 
Hume  called  himself  a  sceptic,  and  therefore  others  cannot  bo 
blamed  if  they  apply  the  same  title  to  him;  but  that  does  not 
alter  the  fact  that  the  name,  Avith  its  existing  implicjitions,  does 
him  gross  injustice.  If  a  man  asks  me  Avhat  the  2)olitics  of  the 
inhabitants  of  the  moon  aiv,  and  I  rej^ly  that  I  do  not  know; 
that  neither  I,  noi-  any  one  else  have  any  means  of  knuv>'iiig ; 
and  that,  under  tiiese  circnir.staiices  I  decline  to  trouble  myself 
about  the  subject  at  all,  1  do  not  think  he  has  any  right  to  call 
me  a  sceptic.  On  tlie  contrary,  in  replying  thus,  I  concei\e  that 
I  am  simidy  honest  aAd  truthful,  and  show  a  proi)er  regard  for 
the  economy  of  time.  So  Hume's  strong  and  subtle  intellect 
takes  up  a  great  many  problems  about  which  we  are  naturally 
curious,  and  shows  ns  that  they  are  essentially  (piestions  of  lunar 
politics,  in  their  es;-.enee  incapable  of  being  answered,  and  there- 
fore not  worth  the  attention  of  men  who  have  work  to  do  in  the 
world.     And  thus  ends  one  of  his  essays  : 

"  If  we  take  in  hand  any  volume  of  l)i\lnil  \ ,  -t  -riKM.l  ;neia- 
pliysics,  for  instance,  let  us  ask.  Does  it  contain  any  ahstract 
reasoning  concernlnr/  quantity  or  number?     No.     Does  it  con- 


23 

tain  any  experimental  reasoning  concerning  matter  of  fact  and 
existence  ?  Xo.  Commit  it  tlieii  to  tlie  flames ;  for  it  can  con- 
tain nothing  but  sophistry  and  ilhision." 

Permit  me  to  enforce  this  most  wise  advice.  Why  trouble 
ourselves  about  matters  of  wliich,  however  im])ortant  they  may 
be,  we  do  know  nothing,  and  can  know  nothing?  iVYe  live  in  a 
world  which  is  full  of  misery  and  ignorance,  and  the  ]dain  duty 
of  each  and  all  of  ns  is  to  try  to  make  the  little  corner  lie  can 
influence  somewhat  less  miserable  and  somewhat  less  ignorant 
than  it  vras  before  he  entered  it.  J  To  do  this  eflectually  it  is 
necessary  to  be  fully  possessed  of  only  two  l^eliefs  :  the  flrst, 
that  the  order  of  nature  is  ascertainable  by  our  faculties  to  an 
extent  ^vhich  is  practicall}^  unlimited  ;  tlie  second,  that  our  voli- 
tion counts  for  something  as  a  condition  of  the  course  of  events. 
Each  of  these  beliefs  can  bo  verified  experimentalh^,  as  often  as 
we  like  to  try.  Each,  therefore,  stands  upon  the  strongest  foun- 
dation upon  wliicli  any  belief  can  rest ;  and  fonns  one  of  our 
highest  truths. 

If  we  find  that  the  ascertainment  of  the  order  of  nature  is 
facilitated  by  using  one  terminology,  or  one  set  of  symbols, 
ratlier  than  anotlier,  it  is  our  clear  duty  to  use  tlie  former,  and 
no  harm  can  accrue  so  long  as  we  bear  in  mind  that  we  are  deal- 
ing merely  with  terms  and  symbols. )  In  itself  it  is  of  little 
moment  whether  Ave  express  the  phenomena  of  matter  in  terms 
of  spirit,  or  the  phenomena  of  spirit  in  terms  of  matter ;  matter 
may  be  regarded  as  a  form  of  thought,  thought  may  be  regarded 
as  a  property  of  matter — each  statement  has  a  certain  relative 
truth.  But  witli  a  view  to  the  progress  of  science,  the  material- 
istic terminology  is  in  every  way  to  be  preferred.  For  it  con- 
nects thought  with  the  other  plienomena  of  the  universe,  and 
suggests  inquiry  into  the  nature  of  those  physical  conditions,  or 
con-comitants  of  thought,  which  are  more  or  less  accessible  to 
to  us,  and  a  knowledge  of  which  may,  in  future,  help  us  to  exer- 
cise the  same  kind  of  control  over  the  world  of  thought  as  we 
already  possess  in  respect  of  the  material  world ;  whereas,  the 
alternative,  or  spiritualistic,  terminology  is  utterly  barren,  and 
leads  to  nothing  but  obscurity  and  confusion  of  ideas.  ^Tlius 
there  can  be  little  doubt  that  the  further  science  advances  the 
more  extensively  and  consistently  will  all  the  phenomena  of 
nature  be  represented  by  materialistic  formula?  and  symbols. 
But  the  man  of  science,  who,  forgetting  tlie  limits  of  philosoj)hi- 


24 

oal  inquiry,  slitlos  from  these  formula^  aiul  syial)ol>  into  what  is 
commonly  understood  by  materialism,  seems  to  me  to  place  hun- 
self  on  a  level  with  the  mathematician,  who  should  mistake  the 
.v'.s  an<l  y\v.  with  which  he  works  his  .problems,  for  real  entities — 
and  with  this  further  disadvantai:e,  as  compared  with  the  math- 
ematician, that  the  blunders  of  the  latter  are  of  no  practical  con- 
se(pience,  Avliile  the  errors  of  systenmtic  materialism  may  para- 
lyze the  eneroirs  and  destroy  the  beauty  of  a  life. 

T.   IT.    IirXLEY. 


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